Backdrop support system frame



FIG. 1 is a perspective view of a backdrop support system frame showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is front perspective view of backdrop support system frame in an environment of use.

Broken lines in the drawings depict portions of the backdrop support system frame that form no part of the claimed design. 

CLAIM The ornamental design for a backdrop support system frame, as shown and described. 